While it was once thought that fetuses in the womb were largely protected from environmental chemicals, it’s now known that a woman’s exposure while pregnant has the potential to harm the developing baby.

Studies show that babies are exposed to hundreds of potentially toxic chemicals while in the womb.

In fact, a study sponsored by the Environmental Working Group (EWG) tested the umbilical cord blood of 10 newborns and found that the samples contained an average of 200 chemicals … chemicals linked to cancer, brain damage, birth defects and more.

“This is conclusive evidence that babies are being exposed to hundreds of industrial chemicals throughout pregnancy,” said Sonya Lunder, an EWG scientist, told the Associated Press. “The placenta isn’t a magic shield.”

The implications of all these chemical exposures are completely unknown, and while it’s likely impossible to eliminate all exposures (most people already have countless environmental chemicals circulating in their bloodstream), it’s a wise idea to minimize your exposure as much as possible during pregnancy and if you’re planning to become pregnant.

Here we’ve compiled a list of some of the worst chemical offenders for developing babies and their moms.

1. PFOA and PFOS

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are known as perfluorinated chemicals. Aside from being used in the manufacture of Teflon non-stick coatings, they are used in countless items such as food packaging, clothing (especially those that are “no-iron” or “wrinkle-free”), upholstery and personal care products. Numerous studies have linked these chemicals to:

Toxic effects on the liver, immune system and developmental and reproductive organs

Impaired fetal growth

Problems with fertility

In a study published in the January 2009 issue of Human Reproduction it was found that women with the highest levels of PFOA took 60 percent to 154 percent longer to get pregnant than those with the lowest levels. Women with high levels of PFOS took from 70 percent to 134 percent longer.

While eight manufacturers of these chemicals committed to reducing emissions and product content of PFOA and PFOS completely by 2015, and many have reduced by as much or more than 95 percent, it’s best to read product labels and avoid any that may still contain them. Items that commonly contain these chemicals include:

Teflon and other non-stick cookware

Microwave popcorn bags

Packaging for greasy foods

Stain-proof clothing

Carpet and fabric protectors

Flame retardants

2. Bisphenol A (BPA)

BPA is one of the world’s highest production-volume chemicals, and it’s found at detectable levels in the blood of more than 90 percent of the U.S. population. BPA is widely used in:

Plastic water bottles

Plastic gallon milk bottles

Plastic microwavable plates, ovenware, and utensils

Tooth sealants

Glasses

Food cans, soda cans, etc. (as most have plastic lining in the cans)

Baby toys, bottles, pacifiers, and sippy cups

Make sure your baby is using a bottle made out of BPA-free plastic or, perhaps even better, glass.

The problem is that BPA can leach out of these products during everyday use, contaminating your food and water and causing serious health problems, such as:

Developmental problems in fetuses and infants

Early puberty

Genital deformities

Down’s syndrome

Disrupted reproductive cycles

Structural damage to the brain

Increased cancer rates in certain organs and cell lines

Plastic that contains BPA carries the #7 recycling symbol so never use those bottles or give them to your children. BPA-containing plastic may also be called polycarbonate, lexan or polysulfone.

Furthermore, according to a Enviromental Health Sciences November 2011 statement “A new study finds its (BPA) reach goes even further. Researchers detected trace amounts of the estrogen-like compound in a wide variety of paper products most of us touch every day, including toilet paper, paper towels, newspapers and business cards.

These paper products represent another source of BPA exposure for people, according to the study’s results, which are published in the journal Environmental Science and Technology. While levels don’t compare to those found in food and are lower than levels measured in thermal paper receipts, the sheer variety of paper products identified with detectable levels of the chemical suggests widespread contamination.”

Taking measures to minimize exposure to paper products may include seeking products with labels that state “No BPA” and also using more online computer communications to pay bills, electronic files, etc. using less paper products overall.

3. Phthalates

These industrial compounds are widely used in hairsprays, perfumes and cosmetics. Animal studies on certain phthalates have shown the chemicals may cause a variety of problems, including reproductive and developmental harm, organ damage, immune suppression, endocrine disruption and cancer.

In a study published in the May 2005 Environmental Health Perspectives, it was found that pregnant women exposed to common levels of phthalates might have baby boys with smaller genitals and incomplete testicular descent.

Baby boys born to moms with high levels of phthalates in their systems have a 10-times greater chance of suffering reproductive damage.

The higher the woman’s exposure, the more likely the baby’s reproductive health would be harmed. The study also reported that changes occurred at phthalate levels found in 25 percent of U.S. women.

In fact, among the women with the highest exposures (this 25 percent of the women), their sons were 10 times more likely to have a shorter-than-expected distance between the anus and the base of the penis, which is an indicator of impacts on their reproductive systems. Further, another study in Environmental Health Perspectives linked phthalates found in household dust to rhinitis, eczema and asthma in children.

Many soft plastics like plastic wrap, plastic storage containers and toys contain phthalates that can outgas into your food and air. With toys, small children may put them in their mouths and ingest phthalates that way. However, personal care products, including nail polish, mascara, fragrances, shampoos and conditioners, lotions, hair growth formulations, antiperspirants, and sunscreen, are a large exposure source.

Your best bet at limiting your exposure is to avoid using plastic when storing your food and drinks, and diligently read the back of cosmetic labels.

4. Disinfection Byproducts (THMs and HAAs)

When the chlorine used to disinfect tap water comes into contact with other naturally occurring elements in water, it forms dangerous byproducts, which include trihalomethanes (THMs) and haloacetic acids (HAAs).

According to EWG, evidence has shown that exposure to HAA during the second and third trimesters of pregnancy may be linked to intrauterine growth retardation and low birth weight. They have also been shown to be toxic to the sperm of rats at concentrations as low as 10 parts per billion, and to cause a range of neurological effects.

Studies have linked THMs with low birth weight and neurological abnormalities in infants, along with increased incidences of neural tube defects, small body length, and small head size in women drinking water containing 400 ppb THMs. Levels of THMs between 80 and 100 ppb and above are associated with increased incidences of neural tube, central nervous system, and major cardiac birth defects.

You can be exposed to disinfection byproducts two ways: by drinking chlorinated tap water, or through showering, bathing or swimming in chlorinated water. Studies show that showers and baths may contribute more to your total exposure to THMs and other disinfection byproducts than drinking water. When you shower or take a bath, the warm water opens up your skin’s pores, making it like a sponge for chlorine, and you also absorb the chemicals when you breathe in the steam from the shower.

This is why EWG recommends filtering not only your home’s drinking water, but also the water you shower or bathe with.

If you are pregnant, planning to become pregnant or have small children in the house, filtering your shower’s water is a simple way to cut back on the potential risks from disinfection byproducts.